/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package mj.ocraptor.extraction.tika.parser.chm;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

import mj.ocraptor.extraction.tika.parser.chm.accessor.DirectoryListingEntry;
import mj.ocraptor.extraction.tika.parser.chm.core.ChmExtractor;
import mj.ocraptor.extraction.tika.parser.html.HtmlParser;

import org.apache.tika.exception.TikaException;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.mime.MediaType;
import org.apache.tika.parser.AbstractParser;
import org.apache.tika.parser.ParseContext;
import org.apache.tika.sax.BodyContentHandler;
import org.apache.tika.sax.XHTMLContentHandler;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;

public class ChmParser extends AbstractParser {

  /** Serial version UID */
  private static final long serialVersionUID = 5938777307516469802L;

  private static final Set<MediaType> SUPPORTED_TYPES = Collections
      .unmodifiableSet(new HashSet<MediaType>(Arrays.asList(MediaType
          .application("vnd.ms-htmlhelp"), MediaType.application("chm"), MediaType
          .application("x-chm"))));

  @Override
  public Set<MediaType> getSupportedTypes(ParseContext context) {
    return SUPPORTED_TYPES;
  }

  @Override
  public void parse(InputStream stream, ContentHandler handler, Metadata metadata,
      ParseContext context) throws IOException, SAXException, TikaException {
    ChmExtractor chmExtractor = new ChmExtractor(stream);

    // metadata
    metadata.set(Metadata.CONTENT_TYPE, "application/vnd.ms-htmlhelp");

    // content
    XHTMLContentHandler xhtml = new XHTMLContentHandler(handler, metadata);
    xhtml.startDocument();

    for (DirectoryListingEntry entry : chmExtractor.getChmDirList().getDirectoryListingEntryList()) {
      if (entry.getName().endsWith(".html") || entry.getName().endsWith(".htm")) {
        xhtml.characters(extract(chmExtractor.extractChmEntry(entry)));
      }
    }

    xhtml.endDocument();
  }

  /**
   * Extracts data from byte[]
   */
  private String extract(byte[] byteObject) throws TikaException {// throws
                                                                  // IOException
    StringBuilder wBuf = new StringBuilder();
    InputStream stream = null;
    Metadata metadata = new Metadata();
    HtmlParser htmlParser = new HtmlParser();
    BodyContentHandler handler = new BodyContentHandler(-1);// -1
    ParseContext parser = new ParseContext();
    try {
      stream = new ByteArrayInputStream(byteObject);
      htmlParser.parse(stream, handler, metadata, parser);
      wBuf.append(handler.toString() + System.getProperty("line.separator"));
    } catch (SAXException e) {
      throw new RuntimeException(e);
    } catch (IOException e) {
      // Pushback overflow from tagsoup
    }
    return wBuf.toString();
  }

}
